Merkel cell carcinoma (MCC), traditionally considered to be a rare form of skin cancer, has become more commonly reported in recent years. MCC may be very aggressive and often metastasizes.
Believed to arise from Merkel cells, which are pressure receptors in the skin, this skin cancer is more common in the elderly >50 years of age. It occurs on areas commonly exposed to sunlight, most often the head and neck.
Ultraviolet radiation has been implicated as a factor in developing MCC, due to the frequent occurrence of the tumor on sun-exposed skin. Immunosuppression following organ transplantation and other immune-deficiency states are also associated with its development.
MCC usually presents as a solitary reddish pink, shiny papule or nodule (Fig. 31.50).
MCCs spread through the lymphatic system and multiple smaller seedlings can develop around the main tumor. With a nearly 40% recurrence rate, MCC may spread to lymph nodes in the neck, axillae, and groin.
Unless there is a high degree of suspicion, the diagnosis of MCC is usually made after a biopsy is performed.
After general examination, including evaluation of local lymph nodes, staging imaging investigations may be arranged to determine whether the tumor has spread to other sites.
Management